Hiram s



(No Model.) 2 Sheets-Sheet 1 H. s. MAXIM.

EOT AIR 0R GAS ENGINE.

No. 293,185. Patented feb. 5, l88 4,

(N0 Mqdel.) I H. S.MAXIM.

HOT AIR 0R GAS ENGINE.

No. 293,185. 4 Patented Feb. 5, 1384.

2 Sheets-Sheet 2.

fittest: Inventor N. PETERS, Phclo-lnhognpllv. Wnhinglon. n.c

,PATENi HIRAM s. MAXIM, o1 rams, FRANCE.

HOT-AIR o R ,GAS ENGINE.

SPECIFICATION forming part of Letters Patent No. 293,185, dated February 5, 1884.

Application filed January 31, 1883. (No model.)

To aZZ whom it may concern.-

Be it known-that I, HIRAM S. MAXIM, a

citizen of the United States, residing in Paris,

in the Republic of France, have invented certain new and useful Improvements in Hot-Air or Gas Engines, of which the following is a specification, reference being had to the drawings accompanying and forming a part of the same.

. The main object of my invention isto utilize 1n an engine driven by heated air a single cylinder for compressing or pumping the air that around the flame or fire chamber in its passage to the working end of the cylinder, and also in a method of increasing the efficiency of an air or gas engine by adding a small portion of cool air to the gasesissuing from the fire before theyact upon the piston, all as hereinafter described. I i

In the accompanying drawings I have illus trated an engine constructed in. accordance with my invention as above stated, and I will now proceed to describe the same in detail.

Figure 1 is a View of the engine complete in side elevation; Fig. 2, a vertical sectional view of the same. Fig. 3 is an enlarged plan View of the valve mechanism located at the working end of the cylinder. Fig. 4 is an end view, partly in section, of the working end of l the cylinder.

Similar letters of reference indicate corresponding parts. H

Letters AA designate ahorizontal cylinder secured to or forming part of a metal casting that constitutes the frame or body of the engine. 1

. Bis a piston of thekind ordinarily employed inlair or gas engines O, the piston-rod working through a suitable stuffing-box in the cylinder-head a.

I) isthe cross-head; E, the connecting-rod,

"same.

and F the crank-shaft carrying a heavy flywheel, F.

' The supporting-base" A of the engine is holward. In the wall of the base A"or the chamber G'isan air-inlet, T. Above the cylinder A is alsoa chamber, G, which extends around the end of the cylinder, as shown, communication between the chamber and interior of the cylinder being established by a valve, b, opening outward. Both valves Z2 Z) are closed. by springs s. A fire-box, H, with perforated bottom,is mounted above the cylinder A. Be-

low the fire-box is a perforated pan, H,which' is located in a chamber or air-space, K. The firebox is contained within a cylindrical casing, K, of such diameter as to leave an annular space around the box. L is a cover for the casing, which may be removed for adding fuel. when necessary, and which is at other times clamped down by a screw, 1, passing through a yoke, L.

M is a chamber or air-space communicating with the space between the fire-box and the casing K, and extending alongthe top of the cylinder A, and partly around the end of the N is a slide-valve working in the bottom of the space K. It opens communication between the chamber G and the space K below the fire, or between the chambers G and M,or between chamber G and both chambers K and M, according to its position.

A lever, O, is pivoted to the cylinder-head a. To one end is connected a rod, o, that op; crates the slide-valve N. To the other end is connected a rod, 0, hinged to one arm of a bell-crank lever, 1, within a. hollow base, A. A flexible diaphragm, R, is placed near the bottom of the base A, and a pin, 7", attached to it, bears against the lower arm of lever P.

In the head a of the cylinder A are set two valves, V V, the first of which is closed by a spring, and opened by a cam,WV, on the crankshaft. The valve V opens into, a chamber, m, separated from the chamber M and open to the air by a suitablepassage, m, Fig.4.

. IOO

The operation of an engine constructed in the manner described is asfollows: The en'- gine is started by hand, the piston being moved by this means toward the cylinder-head a, drawing in air through the hole T and valve 1). Then as the piston is started forward the air contained in the cylinder A is forced out through the valve Z) into the chamber G and up through the slide-valve N. The charge of heated and expanded air that is by this means forced down the annular space between the fire-box and easing K out into the chamber M enters the cylinder A by the valve V and assists in forcing the piston forward. The cam \V closes valve V at the proper moment, so that the piston, by-the momentum of the flywheel, may come back again, the heated air escaping from the cylinder through the ex haust-valve V, which is opened by cam W at the moment when valve V is closed. when valve V is again opened, the expanded air enters the cylinder and pgopels'the piston P forward, thus causing a fresh charge of air to be forced through the fire, and storing in the chamber G a charge of air under compression, to be used on the next stroke. The diaphragm It, slide-valve N, and intermediate connections operate as a regulator. WVhen the engine is started, or when running slow, the diaphragm is in its normal position and the slide-valve pushed over to the left, opening the port a and causing all the air pumped into the chamber G to be forced through the fire. When the engine runs too fast, or when the air drawn in through the valve bis increased beyond a point, which maybe determined by adjusting a slide, t, over the opening T, a partial vacuum is formed in the chamber G. This raises the diaphragm and shifts the slide-valve to the right, whereby a part only of the air will be forced through the fire, the remainder being forced up through the port '11, and down through port at, being in this way shunted around the fire. continues to increase, the slide-valve will be moved to the right until all the air is diverted or shunted from the fire.

In practice the valve N and its appurtenances should be so adjusted that in the normal operation of the engine asmall portion of the air will be forced through the valve into the chamber M, so that it may combine with the air that is forced from the fire-box. By this means oxygen is added to the flaming products driven into the chamber M, forming C0 of the CO from the fire and producing a flame which extends into the chamber M, thus causing a greater degree of expansion than would be the case were all the air to pass through the fire. I

It is evident that the engine which I have described may be used as a gas as well as an air engine without material changes in its mechanical construction; for, supposing the fire to be replaced by a suitable gas-flame, and a If the speed of the engine mixture of air and gas to be introduced to the box II, it is ignited and forced down into the chamber M and through valve V, exerting the same effect upon the piston 13 as the heated air or burning gaseous products from a charcoal fire.

In the drawings I have shown an annular space around the fire-box, down which the products of cumbustion are forced. For many reasons the reverse of this construction is desirable, viz: that the air should be forced up through the. space and down through the fire, as by this means the exterior of the engine would be kept cooler. I regard this construction as within the scope of my invention.

Many details of construction herein shown in part or entire I have not described at length,

as they are well known in the art and em-' ployed in mechanisms of this kind-for instance, the materials used in the construction of the engine, the means of maintaining a draft through the fire when the engine is not in operation, and the like; but,

-Having described and specifically pointed out what I regard as my invention, what I claim is- 1. In an air or gas engine, the combination of a cylinder and piston, a flame or fire cham ber, passages or chambers of communication from said flame or fire chamber to opposite ends of the cylinder, valves located at oppo site ends of the cylinder, those at one end operating, in conjunction with the piston, as a compressor, and those at the other end for admitting and exhausting air to and from the working end of the cylinder, passages and a valve arranged to connect said passages of communication independently of the fire or flame chamber, and automatic means for operating said valve to shunt all or a portion of the air entirely from said flame or fire chamber in its route from the pumping to the work ing end of the cylinder, substantially as described.

2. In an air or gas engine having a firechamber in communication with the opposite ends of its cylinder by means of suitable passages and valves, and suitable shunt-passages arranged to connect the opposite ends of the cylinder independently of the fire-chamber,

a valve arranged to control the flow of air through said shunt-passages, an air space-or chamber connected with the pumping end of the cylinder, a flexible diaphragm, forming one of the walls of said space or chamber, and devices conneeting said diaphragm with the valve controlling'the shunt-passages, and arranged to move said valve in proportion to the pressure on the diaphragm, substantially as and for the purpose set forth.

3. The method herein described of regulating the speed of an air or gas engine, which consists in shunting, through a route distinct from and independent of the fire-chamber, a portion or the whole of the air or gas forced eesuss 3 into the engineyas and for the purpose set In testimony whereof I have hereunto set forth. 1 my hand this 4th day of January, 1883.

4; The method herein described of increas ing .the efficiency of an air or gas engine, -the HIRAM S. MAXIM. 5 same consisting in adding a, small portion of r cool air to the gases issuing from the fire 0n Vitnesses: their way tothe cylinder, essentially as set ROBT. M. HOOPER,

DAVID T. S. FULLER.

forth. 

